AN ISLAND-WIDE blackout struck Cuba on Friday for the second time last week as the nation of nearly 10 million people grapples with fuel shortages stemming from a US energy blockade. While total blackouts have become increasingly common in the Caribbean country, it’s unusual for back-to-back ones to hit just days apart. Authorities in Cuba said the cause of the blackout was a “fluctuation in the parameters” following a failure in a line connecting the provinces of Santa Clara and Sancti…